﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;
using System.Security.Cryptography;

namespace IPMS.Library
{
    public class UserLibrary
    {
        public static string hashMD5Password(string password)
        {
            if(!String.IsNullOrEmpty(password))
            {
                // Create a new instance of the MD5CryptoServiceProvider object.
                MD5 md5Hasher = MD5.Create();

                // Convert the input string to a byte array and compute the hash.
                byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(password));

                // Create a new Stringbuilder to collect the bytes
                // and create a string.
                StringBuilder sBuilder = new StringBuilder();

                // Loop through each byte of the hashed data 
                // and format each one as a hexadecimal string.
                for (int i = 0; i < data.Length; i++)
                {
                    sBuilder.Append(data[i].ToString("x2"));
                }

                // Return the hexadecimal string.
                return sBuilder.ToString();
            }
            else{
                return null;
            }
        }

        // Verify a hash against a string.
        public static bool verifyPassword(string password, string hashedPassword)
        {
            // Hash the input.
            string hashOfInput = hashMD5Password(password);

            // Create a StringComparer an compare the hashes.
            StringComparer comparer = StringComparer.OrdinalIgnoreCase;

            if (0 == comparer.Compare(hashOfInput, hashedPassword))
            {
                return true;
            }
            else
            {
                return false;
            }
        }
    }
}